Granting paid access...?

This doesn't quite belong in lj_dev, but I can't find a better place for it. It's a question about administrating a livejournal server, I guess. I asked on the goathack community, but got no response, so now I ask here...

Using the ljcom codebase, how do you go about giving a user "paid" access? Is there some user friendly way to do it, rather than manually changing stuff in the database? Perhaps you use the "payment_credit" admin command? But I'm not sure what I would use for the code/payid... Perhaps the payment process could be covered in the LJ internals faq?